Chain tightener



l. WIWORLOWl CHAIN TIGHTENEH. APPLICATION FILED APII. s. I92I.

1,405,248.- Patented Jn.31,1922.

gnam/Ifo@ unirse STATES PATENT OFFHCE- isAfic w. wonnow, or WALTERS,OKLAHOMA.

CHAIN TIGHTENER.

-iaoaaia To all whom t may conectan A- labor.

Beit known that I, ISAAC WV. WonLow, a citizen of the United. States,residing at Walters,in the county of Cottonand State of Oklahoma, haveinvented certain vnew and useful Improvements in Chain Tighteners, ofwhich the following is a specification.

This invention relates to a spring idler or chain tightener for a rotarydri'llingr'ig.

The primary object of the inventionfre-I sides in the constructiono-fjaspring idler particularly designedv for use in connection withrotary drillingmachinery whereby the endless driven chain will beprevented `from leaving the sprocket wheels and at all times bemaintained vtaut thus Overcoming any jerking due to hard drilling, andincidently saving wear and tear on the working parts.. One 0f theobjects of the invention consists in the provision of a` novel landimproved spring idlerdesigned foriheavy drive chains ysuch asis used onrotary drilling rigs struction, consisting of. comparatively few partstherefor inexpensive to manufacture, practical and highly efficient inoperation, strong and durable, capable of universal use in connectionwithyvarious types of drilling A machinery andotherwise'constitutingavery Vtended purpose wherever used.

With these objects in view and others important yet necessary adjunctfor its inwhicli will be suggested` and manifest as the purpose andnature of my invention are revealed in the following;V specification anddrawings wherein I have showna preferred embodiment thereof.

Figure l shows the invention as applied in use in connection with arotary drilling rig. Y

f F'ig. 2 is a front view of the spring idler mechanism.

Fig. 3 is a perspective of one of the spring carrying arms.

Fig. 4 1s a detail view of a connecting block.

vLipplation filedrAplil 6,V 1921. Serial No. 459,1'72.y i

and' very*important object ofthe Referring now to the` drawings whereinlike parts designate corresponding ,parts Specification ofLetterslatent. j Patented Jail 3171192722.

tliroughoiitthe speciicatiomy designates av rotary drilling rig whichrevolves very rap-l idly, being driven by the usualfsproeket wheel 6vmounted in its bearings/7 jjfrom the draw works which I have designatedin itsi entirety by numeral 8, said draw works loe`r ing alsoA provided.with la sprocket-9 and Vof course receiving the endless chainlO trainedabout the sprocket 7 above referred' to.A

- In actual practice, the draw works-are positioned at aconsiderabledistance from the rotary drilling rig and consequently somepro-V vision must be had and ii'itroducedbetweenA the same to maintainthe Vendless chain in a y taut condition to preventsaid chain'ffromjumping Qr'leaving the sprocket wheelssoy i' that thedrill-ing:maehinery will Inotfcease operating.. yThe direct pull isv onthe bottom chain l1 and hence 'my'novel and: improved i chain tighteneris designed to depress ortake up the slack' inthe i'ipper"cliainl2` inthe mannernow to be described in detail.

The chaintightenerstructure which isin.- terposed loetweentli'evdrilling rig andthe draw works, primarily consists of a sill Vor base 13to whichis permanently secured'the parallel, Ushapedsupports 14, '15which are leach bolted as at 16-to said sill thus constituting 4a rigidstructure'.` The' U-shaped supy porting members above referred to whichare a i preferablyvmade Vof metal are bent intermediate of their sidesas shown at 17 having .pivotally connected thereto thearms r18, 19 f'for supporting the'intermediate shaft 2O asv v clearly shown in F ig. 2of the drawing. It Y will be observed that the arm-l9'is provided @awith a slot 2O near its outer-end permitting `relative y'movement of therespective arms and theshaft carried therebyfor the vpurposepresently'to appeal-.

The inner ends ofthelarms' 21u-f2.2, are i.

provided with aperturestherein, blocks 23 being'adapted to straddle theends of saidv arms, 'the vertical faces 24 of said blocks be! 'ing alsoprovided with apertures 25'- for alignment with the apertures intheinner ends of the arms to receivethe shaft 2O above,

p referred to. Byzthis construction, it vvillbey j readily seen that theshaft 20 which extends .Y

through and connects the ends of the arms is also heldin positionbytheblocks 24 and .110

due to the relative movementrof the said arms, said shaft may bevertically adjusted to its proper positionfand maintain the upper chainl2 taut. y Intermediate of the shaft 9.0

and between the supports, I have provided a freely rotatable sprocketwheel 26 beneath which the chain l2 travels and have also providedvertical supporting hangers 27, 28 which are in the nature of rods andprovided with end bearings 29 for receiving the shaft 20, suitableresilient springs 30 `being inter.- posed between the top 3l of thesupport and the bearings 29 whereby considerable downward pressure maybe exerted on the shaft 20 to maintain the sprocket 26 in engagementwith the top chain l2 and thus keep the same taut.` By reason ofpositioning the hangers and the resilient springs in the manner aboveindicated,- it will be readily apparent that the tendencyv of the chainto become loose or slack is overcome whether it be due to stretching ofthe same or otherwise and furthermore by reason of the relativeadjustment of the arms, the shaft may be raised or lowered toitsadjusted position to properly move the freely rotatable sprocket wheel2G carried. thereby in engagement with the end-l less lchain.

ln the accompanying' drawings, l have illustrated my invention embodiedin one form by way of example, andwhich in practice has been found to beYhighly satisfacn tory in yobtaining the desired results. lt will beobvious however that other embodiments may be adopted and that variouschanges in the details ofconstruction may be resorted to by thoseskilled in the art withoutV departing from the spirit and scope of theinvention. lt is furthermore uiiderstood that the invention is not'necessarily limited or restricted to the precise elements V iiectedintermediate the' sides thereof, a shaft fand idler sprocket carriedthereby supported by said arms, and movable therewith, and means forexerting downward pressure on said shaft to maintain thecidler sprocketin engagement with an endless chain.

2. fi chain tightener comprising a support,separably connected armspivotally attached to said support intermediate the sides thereof, ashaft and idler sprocket carried thereby supported by said arms betweenthe support and means for exerting downward pressure on said shaft tomaintain the idler sprocket in engagement with an endless chain.

3. A chain tightener comprising parallel supports adapted to be rigidlysecured to a base, separably connected arms pivotally at tachedintermediate the sides of said supA poi-ts, a horizontal shaft and idlersprocket carried thereby held by said arms and positioned between thesupports, and means for exerting downward pressure on said shaft tomaintain the idler sprocket in engagement with an endless chain. y

Il. A chain tightener comprising a pair of parallel, U-shaped supportsadapted'to be rigidly secured to a base, separably connected armshaving` apertures in their inner ends pivotally attached intermediatethe sides of said supports and a connecting block provided with anaperture therein straddling the inner ends of said arms, a horizontalshaft and idler sprocket carried thereby passing through the connectedends of said arms and block 'and resilient means for maintaining theidler sprocket in engage ment with anv endless chain.

5, A chain tiglitener comprising a pair of parallel, U-shaped supportsadapted to be rigidly secured to a base, separably connected arms havingapertures in their inner ends, pivotally attached intermediate the sidesof said supports, a connecting block straddling the inner ends of saidarms and provided with apertures'therein, a horizontal shaft and idlersprocket carried thereby passing through the ends of said arms andblock, hangers provided with end bearings for said shaft extendingthrough the top of the supports and resilient springs on the hangersinterposed between the bearings' and supports whereby the shaft andidler sprocket may be maintained in engagement with an endless chain. Y

ln testimony whereof, l affix my signature hereto. Y

SAAG W. VURLOW.

